The application background of J1939 and J1708 protocols in the automotive industry

The application background of J1939 and J1708 protocols in the automotive industry

J1939 protocol (mainstream for commercial vehicles)

Application scenarios:

Mainly used for onboard networks of heavy-duty trucks, buses, and construction machinery vehicles (such as excavators and cranes), supporting high-speed communication of key components such as engines, transmissions, ABS systems, and body controllers.

characteristic:

High standardization level, supporting multi master communication, fault diagnosis, and complex data interaction (such as parameter array numbering PGN).

J1708 protocol (low-speed compatibility scenario)

Application scenarios:

Commonly seen as auxiliary equipment for early commercial vehicles, special vehicles (such as fire trucks, ambulances), or low-cost sensors, displays, etc., for example:

Old style dashboard and air conditioning controller;

Non critical sensors (such as in car temperature and liquid level sensors);

Post installed equipment (such as third-party monitoring terminals).

characteristic:

Based on RS-485 bus, the speed is low and the protocol is simple and easy to implement, but it cannot meet the requirements of high-speed real-time control.